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Help with a new Tube headphone amp blowing fuses

Received a new headphone amp this week to replace one from same manufacturer that is still serving me well but wanted to try a little more power, new amp 1.4 watts versus a .35 watt on the older one. Have about 25 hours on new amp and turned it on this morn loaded CD and after about a minute the music was replaced with an elevated fuzzy noise right before fuse blew, replaced fuse and it blew a second or two after turning unit on, saw nothing unusual going on with the tube glow, replaced New amp with the older amp in system and all is well. What are the possibilities of fault here, would like to handle myself without having to send back to Japan for warranty work.
tooblue
atmasphere's avatar
atmasphere
12,403 posts
 
The tube glowing oddly does not happen all the time.

Remove the power tube and run the unit. Does the fuse blow? If yes => it needs service, probably in the power supply. If no => install the tube and try it again. If you hear odd sounds, tap on the tubes and see if any respond. The socket might be loose (but that usually won't blow a fuse unless its the grid connection on the power tube that is loose) which can make crackling and popping sounds. So you have to sort out which is which. Sounds like it would be a good idea to obtain a spare power tube regardless since they are not all that common.
tooblue OP
2,079 posts
 
atmosphere, thanks for your input, currently out of fuses but did just order some off ebay (damn I miss Radio Shack) and some back up tubes. when the fuses arrive I will remove the two c3m tubes and give it a try and see what happens. Going to try that before taking it to a tech for diagnoses. Unit is brand new and did work well with no issues for at least 20 hours, the first 16 being burn in hours and the last 4 actually listening.
tooblue OP
2,079 posts
 
@raindance , just got my Yamamoto tube headphone amp back from the shop here in Houston and the diagnoses is that it has a bad transformer, that he could not get parts and that he would discard it for me and save me a trip. I have reached out to the factory with no response and was wondering, if it were you, what would your next move be? I am pretty certain at this time there is no quality audio repair in the Houston area
raindance
56 posts
 
test
raindance
56 posts
 
OK, so you have a couple of options:
1. Have the manufacturer send you the part and have someone install it (like me). This assumes the diagnosis is correct.
2. Send it back. I am sure shipping is not a significant percentage of the cost of the unit.
3. Send it to me. It may take a while, as I have a real job :)

You could try Google translate to communicate with the factory. These guys have a reputation to uphold and they should work with you.

I don't know which transformer is evidently bad but a weird hissing noise sure sounded like a bad tube to me. 
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